Audio content is readily available via wide area networks. In particular, Internet radio has become increasingly popular. However, because of the complexity of wide area networks, it is difficult for content owners to accurately determine the number of recipients for particular content items. For example, Internet radio content is typically provided to a user via an information stream and multiple content items (e.g. songs) are provided in the stream. It is difficult to accurately determine when the user has terminated the stream, and therefore difficult to determine which content items have been provided to the user.
The use of the same reference symbols in different drawings indicates similar or identical items.